1. Field of the Invention
The present invention relates generally to a communication system, and in particular, to a signal relay system and method for increasing throughput in a communication system.
2. Description of the Related Art
FIG. 1 is a diagram illustrating a configuration of a signal relay system in a general communication system.
Referring to FIG. 1, the signal relay system includes a source node S, a destination node D, and a relay node R. The source node S transmits a signal to the destination node D, and the relay node R performs a relay operation for signal transmission from the source node S to the destination node D.
The signal transmitted by the source node S may be received at both the relay node R and the destination node D due to the characteristics of the wireless transmission medium. However, a signal-to-Noise Ratio (SNR) γSR between the source node S and the relay node R can be higher than an SNR γSD between the source node S and the destination node D, and this indicates that the signal transmission from the source node S to the relay node R is superior to the signal transmission from the source node S to the destination node D in terms of the throughput. In particular, there is a possible case where the signal transmitted by the source node S is safely received at the relay node R, but is never received at the destination node D. In this case, the signal transmission from the source node S to the relay node R is surely superior to the signal transmission from the source node S to the destination node D in terms of the throughput, because the signal transmission from the source node S to the destination node D is completely impossible.
Generally, in a multi-hop mode, the signal transmitted by the source node S is safely received at the relay node R, but is never received at the destination node D. In the multi-hop mode, the relay node R must relay all signals received from the source node S to the destination node D. In order to increase throughput of the communication system in this way, it is important to efficiently perform signal transmission between the source node S and the relay node R and increase throughput between the source node S and the destination node D. Accordingly, there is a need for a signal relay scheme for increasing the throughput of the communication system.